L79 distributor parts identification?
05-12-2024, 05:08 PM
#1
Instructor
Thread Starter
L79 distributor parts identification?
Can anyone provide the number stamped on the "football" and on the centrifugal weights of a 1966 L79 engine. I am unable to get the full centrifugal advance from my distributor. Any help is certainly appreciated. Have been unable to turn up any printed information about what was originally intended.
05-12-2024, 05:29 PM
#2
Team Owner
05-12-2024, 09:08 PM
#3
Le Mans Master
Member Since: Nov 2015
Location: Really Central IL Illinois
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Looks like the mechanical advance is the same as the 300 hp per the GM archives: https://www.gm.com/content/dam/compa...t-Corvette.pdf My 300 hp has a 153 football on the shaft and the advance weight plate is a - 530 CCW so you would get the 30 degrees mechanical advance.
I have never been able to find any p/n or anything to identify the weights. I am thinking they were all the same, but Duke or someone may provide the missing information.
I have never been able to find any p/n or anything to identify the weights. I am thinking they were all the same, but Duke or someone may provide the missing information.
05-13-2024, 04:59 PM
#4
Instructor
Thread Starter
Attempted to order a "530" cam plate " at Zip as per advice on the link provided. They have it listed but when I asked about the ID stamping they were all 726, which seems to not be the one for a 350HP. The shaft with the "football" has no ID stamped on the ones they have so in doubt about that as well. My shaft is stamped 203 or possible 209, and I have no idea what is correct. So looking for help identifying the correct shaft. Has anyone a "530" cam plate they want to sell? Or maybe a source to purchase from a vendor? Also any advice on the proper main shaft would be appreciated. Thanks!
05-13-2024, 09:55 PM
#5
Le Mans Master
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I looked in my stash of old distributors and found a "730" advance weight plate, not the "530" that you are looking for. I don't know the difference in the 700 series and the 500 series. It seems they started the 700 series in 1968 from the quick look I took in the GM Archives. It could be nothing or it could be a change in the relationship of the advance plate positioning of the rotor to the positioning of the point octagon or maybe just the vacuum advance I thought it came out of at 66 Chevelle 327, but the archives say it had a 28 degree advance plate. The slot length confirms the 30 degree advance from my prior attempt to understand the GM system.
Duke or Lars or Tbarb or another more knowledgeable member may have the answer we need. The long way to get an answer is to try to mock up a stand to measure the degrees of advance and rotor position to the point octagon.
Ron
Duke or Lars or Tbarb or another more knowledgeable member may have the answer we need. The long way to get an answer is to try to mock up a stand to measure the degrees of advance and rotor position to the point octagon.
Ron
05-13-2024, 11:04 PM
#6
Team Owner